One limitation associated with pneumatic tires is the need to maintain proper tire air pressure during vehicle operation. A relatively low or high pressure tire can often go undetected for a long period of time, which poses a serious risk of tire failure. While it is prudent to periodically check tire inflation pressure with an air pressure gauge, such checks are generally not conducted.
The concept of providing an on-axle tire inflation system, or what is known as a central tire inflation system (CTIS) or automatic tire inflation system (ATIS), is well known in the art. Such systems remotely or automatically inflate a pneumatic tire rotatably mounted onto the axle of a vehicle via an air distribution system. Typically, an on-board source of pressurized air, such as compressed air from a vehicle air compressor or a hub mounted pump, is used to fill the tire and/or maintain proper tire pressure.
To connect the air source to the vehicle wheel, a check valve is typically disposed through the rim of the wheel. The check valve allows air to flow from the air source into the tire, but inhibits air flow from the tire back to the air source. In a typical check valve application unrelated to the subject environment, a relatively large pressure differential on each side of a valve member assists the valve spring in forcing the valve member against the sealing member to close the check valve. However, in a tire inflation system, the pump pressure on one side of valve member is substantially similar to the tire pressure on the other side of valve member, creating a relatively low pressure differential. Additionally, because the check valve is mounted in the wheel rim and is subjected to centrifugal force of the rotating tire, conventional check valve designs will generally allow back flow of the tire air into the air source when the wheel is rotating at a relatively high speed.